
Smart Machine Smart Decision
SIM5800_Hardware Design_V1.01
23
2018-10-08
Users can power on SIM5800 by pulling down the PWRKEY pin at least 6 seconds (TBD) and then release. This
pin is already pulled up to VBAT in the module, so external pull up is not necessary. Reference circuit is show as
below:
4.7K
47K
PWRKEY
R
VBAT
1K
PMU
Module
Turn on/off
impulse
Figure 9: Power on/off module using transistor
PWRKEY
R
VBAT
1K
PMU
Module
Figure 10: Power on/off module using button
The power on timing is illustrated as the following figure.
115ms
VBAT
PWRKEY
RESET
t>600ms
VIO18_PMU
VIO28_PMU
4ms
80ms
Figure 11: Timing of power on module
4.2.2
Power off
SIM5800 could power off by pull down PWRKEY for at least 1 second. once the module detect the power off
action ,there will be a notice on the screen for users to confirm whether to power off or not.
4.2.3
Reset Function